1. Field of Invention
The invention relates to the field of surgical instruments, and more specifically to improvements in flexible shaft stabilizer devices and surgical tools usable in conjunction therewith.
2. Description of Related Art
In the field of medical instrumentation, flexible shaft stabilization devices are known in the art. Such devices are sold under the name OCTOPUS by the MEDTRONIC company and AXIUS by the GUIDANT company. Particularly in Coronary Artery Bypass Graft (CABG) procedures, such devices are used to stabilize the surface of the beating heart muscle at the site where an anastomosis will be formed. The devices commonly have a malleable shaft of a certain length, with a stabilizer foot or other apparatus at a distal end of the shaft. The apparatus is positioned as required, then a lead screw at a proximal end of the shaft is turned by some manner of handle to secure the shaft rigidly in place. The turning of the lead screw commonly applies tension to a fiber, such as a metal wire or braided cable. Tensioning of the cable compresses the flexible shaft, and secures it rigidly into an intended straight or curved position. These devices are considered an improvement over other stabilizers, because the length of the shaft can be positioned away from the surgical field, as compared to fixed-arm stabilizers that may impede access and vision to the surgical site.
These devices are not without drawbacks, however. Among the drawbacks are difficulties with tensioning the fiber or cable that compresses the flexible shaft. It has also been observed that after the first actuation of the shaft in such devices, subsequent actuations with equal turning of the actuator as the first actuation did not achieve the desired or necessary stiffness to hold the intended straight or curved position of the shaft. Further, currently available shafts are often not conducive to convenient positioning of the distal end of the flexible shaft at the surgical site by the surgeon, even when the shaft is in the relaxed state. Further, still detrimental wearing and gall can occur at the cam of the tensioning mechanism, including the generation of metal particulate that may compromise an otherwise sterile surgical field. Turning of the handle to tension the fiber and position the shaft appropriately is also a time consuming and cumbersome task often requiring assistance from a second medical professional. A great deal of force is typically required to actuate the handles of known flexible shaft devices having high shaft stiffness.
In addition to the drawbacks of known flexible shaft devices, a surgical apparatus secured to a distal end of a flexible shaft, or even a rigid retractor, may have its own drawbacks. A suction device for grasping and manipulating tissue such as those sold by the MEDTRONIC company under the brands STARFISH or URCHIN, or those sold by the GUIDANT company under the brand XPOSE may be used with a flexible shaft. The former lack the ability to dynamically adapt to moving tissue, such as the beating heart, however, and rely instead on the resiliency of the material comprising the suction device to better conform to the targeted tissue. The latter, on the other hand, are awkward, difficult to manipulate, and prone to user error.
Another apparatus that may be used in conjunction with a flexible shaft, though also with other devices, is a bendable suction bridge. Suction bridge stabilizers are used to immobilize tissue at a surgical site, for example the surface of the beating heart. These bridge devices typically place a stabilizing arm on either side of the target vessel, and use downward pressure to immobilize the tissue. Suction may be provided to secure the tissue to the stabilizer. However, it is desirable to position the suction devices perpendicularly to the heart surface, which itself is curved, the particular curvature individual to each patient. Rigid devices cannot accommodate this curvature in the heart. Moreover, is cumbersome to provide a suction line individually to each arm, however, as is commonly done in such devices. Likewise, it is desirable to avoid obstructing the vessel between the arms of the bridge, as a flat transverse bridge of known bridge devices might do.
Some devices in the prior art, including those sold under the OCTOPUS and ACROBAT brands, do not present a bendable bridge, and are therefore less able to adapt to the variety of tissue configurations a surgeon finds in practice. Others, such as those sold under the FLEXITE brand, are bendable at the bridge but not at the pods surrounding the arms, and require multiple vacuum inlets to each arm. Accordingly, an improved suction foot device that better conforms to the targeted tissue is desirable in the art.